Antiacne Medications — MCQs
Which of the following are treatment options for acne vulgaris?
A 24-year-old woman presents with multiple nodular, cystic, and pustular lesions on her face and shoulders for 2 years. What is the drug of choice for her treatment?
What is the maximum cumulative dose of isotretinoin for acne treatment?
A 17 year old girl had been taking a drug for the treatment of acne for the last 2 years, which has led to pigmentation. Which drug could it be?
Benzoyl peroxide acts in acne vulgaris by
23 years old woman complains of recurrent acne over her face. History revealed that she had taken topical antibiotics for her acne without any significant improvement. Which one of the following tetracyclines is most preferred for her acne?
A 25-year-old male university student presented with a history of multiple tick bites 45 days prior, followed by recurring episodes of high-grade fever, headache, myalgias, arthralgias, nausea, and occasional vomiting. Each episode lasted approximately 6-7 days with symptom-free intervals of 9-10 days. Physical examination revealed mild splenomegaly and skin lesions. A Wright stain of the patient's peripheral blood smear was performed. What is the first oral drug of choice for this patient?
Drug Induced Lupus is caused by all except
Best drug for the condition shown below is: (NEET Jan 2018)
Which of the following reduces the efficacy of oral contraceptives?
Antiacne Medications Indian Medical PG Practice Questions and MCQs
Question 1: Which of the following are treatment options for acne vulgaris?
- A. Isotretinoin
- B. All of the options (Correct Answer)
- C. Topical erythromycin
- D. Oral Minocycline
Explanation: ***All of the options*** - All listed options (Isotretinoin, Topical erythromycin, and Oral Minocycline) are well-established and commonly used **treatment options for acne vulgaris**, depending on the severity and type of acne. - The choice of treatment often follows a stepped approach, starting with topical agents for mild to moderate acne and progressing to oral medications like antibiotics or isotretinoin for more severe or resistant cases. *Isotretinoin* - **Isotretinoin** is a powerful oral retinoid primarily used for **severe, recalcitrant nodular acne** that has not responded to other treatments. - It works by reducing sebum production, follicular hyperkeratinization, inflammation, and the growth of *P. acnes*. *Topical erythromycin* - **Topical erythromycin** is an **antibiotic** used to treat mild to moderate inflammatory acne by reducing the growth of *Cutibacterium acnes* (formerly *Propionibacterium acnes*) and decreasing inflammation. - It is often combined with other topical agents like benzoyl peroxide to minimize the development of **antibiotic resistance**. *Oral Minocycline* - **Oral minocycline** is a **tetracycline antibiotic** used for moderate to severe inflammatory acne. - It reduces bacterial populations on the skin and exhibits **anti-inflammatory properties**, making it effective for widespread or deeper lesions.
Question 2: A 24-year-old woman presents with multiple nodular, cystic, and pustular lesions on her face and shoulders for 2 years. What is the drug of choice for her treatment?
- A. Isotretinoin (Correct Answer)
- B. Azithromycin
- C. Doxycycline
- D. Acitretin
Explanation: ***Isotretinoin*** - This patient presents with **severe nodulocystic acne**, characterized by multiple nodular, cystic, and pustular lesions, which is the primary indication for oral isotretinoin. - Isotretinoin is a potent systemic retinoid that **reduces sebum production**, inhibits _Propionibacterium acnes_, normalizes keratinization, and has anti-inflammatory effects, leading to significant and often long-term remission. *Azithromycin* - Azithromycin is an **antibiotic** that can be used for inflammatory acne, but it is typically reserved for patients who cannot tolerate or are resistant to other tetracycline-class antibiotics. - While it has anti-inflammatory properties, it is generally **less effective for severe nodulocystic acne** compared to isotretinoin. *Doxycycline* - Doxycycline is a **tetracycline antibiotic** commonly used for moderate to severe inflammatory acne due to its anti-inflammatory effects and ability to reduce _P. acnes_ bacteria. - However, for **severe nodulocystic acne**, systemic antibiotics like doxycycline are often insufficient as monotherapy and **isotretinoin is the preferred treatment** for its superior efficacy in such cases. *Acitretin* - Acitretin is a systemic retinoid primarily used for **severe psoriasis** and other keratinization disorders. - It is **not indicated for the treatment of acne** and has a different safety profile and mechanism of action compared to isotretinoin.
Question 3: What is the maximum cumulative dose of isotretinoin for acne treatment?
- A. 30-60 mg/kg
- B. 60-90 mg/kg
- C. 90-120 mg/kg
- D. 120-150 mg/kg (Correct Answer)
Explanation: ***120-150 mg/kg*** - The goal of **isotretinoin cumulative dosing** is to achieve long-term remission and reduce the risk of relapse. - A cumulative dose in the range of **120-150 mg/kg** has been shown to optimize treatment outcomes for severe or recalcitrant acne. *30-60 mg/kg* - This range is typically considered too low to achieve the optimal **cumulative dose** for sustained remission in severe acne. - Doses within this range might be used in some cases for milder forms of acne or in patients with significant side effects, but not as the standard maximum. *60-90 mg/kg* - While this is closer to an effective cumulative dose, it still often falls short of the recommended range for maximizing the long-term efficacy and reducing relapse rates in patients with severe forms of acne. - Studies suggest that higher cumulative doses correlate with better treatment success and fewer recurrences. *90-120 mg/kg* - This range is often considered a minimal target for a **cumulative dose**, especially at the higher end of the range (120 mg/kg). - While effective for many patients, aiming for the upper end (120-150 mg/kg) often provides a more robust and durable response, particularly in more severe or nodular acne.
Question 4: A 17 year old girl had been taking a drug for the treatment of acne for the last 2 years, which has led to pigmentation. Which drug could it be?
- A. Doxycycline
- B. Minocycline (Correct Answer)
- C. Clindamycin
- D. Azithromycin
Explanation: ***Minocycline*** - **Minocycline** is a **tetracycline** antibiotic commonly used for acne and is notorious for causing various forms of **pigmentation**, including blue-gray discoloration of the skin, scars, and teeth, especially with long-term use. - This pigmentation is due to the formation of **insoluble chelates** of minocycline with iron and melanin within tissues. *Doxycycline* - While also a **tetracycline**, **doxycycline** is less commonly associated with significant **skin pigmentation** compared to minocycline at standard acne treatment doses. - Its side effect profile for pigmentation usually involves **photosensitivity** or **tooth discoloration** in children, not generally diffuse skin discoloration in adolescents. *Clindamycin* - **Clindamycin** is a **lincosamide antibiotic** primarily used topically or orally for acne, but it does not cause **pigmentation** as a known side effect. - Its main systemic side effect concern is **Clostridioides difficile-associated diarrhea (CDAD)**. *Azithromycin* - **Azithromycin** is a **macrolide antibiotic** and is not typically associated with **skin pigmentation** as a side effect. - It is sometimes used for acne, but its side effects are primarily **gastrointestinal** (nausea, vomiting, diarrhea).
Question 5: Benzoyl peroxide acts in acne vulgaris by
- A. Acts as oxidizing agent
- B. Decreased sebum production
- C. Reduces epithelial proliferation
- D. Decreasing bacterial count (Correct Answer)
Explanation: **Decreasing bacterial count** - Benzoyl peroxide is a potent **antimicrobial agent** that works by releasing oxygen free radicals, which are toxic to the anaerobic *Propionibacterium acnes* (now *Cutibacterium acnes*) bacteria. - This reduction in bacterial load directly addresses one of the primary pathogenic factors in **acne vulgaris**. *Acts as oxidizing agent* - While benzyl peroxide does act as an oxidizing agent, this description is a mechanism of how it works, not its primary therapeutic effect in acne. - The oxidative action primarily destroys bacterial cell walls and proteins, leading to its **bactericidal effect**. *Decreased sebum production* - Retinoids (e.g., isotretinoin) are primarily responsible for **decreasing sebum production**, which is a key factor in acne pathogenesis. - Benzoyl peroxide does not significantly alter the activity of sebaceous glands. *Reduces epithelial proliferation* - Topical and oral retinoids (e.g., tretinoin, isotretinoin) function by modulating **epithelial keratinization** and proliferation, preventing the formation of comedones. - Benzoyl peroxide does not directly target epidermal cell turnover but rather exhibits a mild **comedolytic effect** indirectly.
Question 6: 23 years old woman complains of recurrent acne over her face. History revealed that she had taken topical antibiotics for her acne without any significant improvement. Which one of the following tetracyclines is most preferred for her acne?
- A. Doxycycline (Correct Answer)
- B. Oxytetracycline
- C. Minocycline
- D. Demeclocycline
Explanation: ***Doxycycline*** - **Doxycycline** is a commonly preferred tetracycline for acne due to its **anti-inflammatory properties** and efficacy against *P. acnes* at sub-antimicrobial doses. - Its **longer half-life** allows for once-daily dosing, improving patient adherence compared to other tetracyclines. *Oxytetracycline* - While effective against *P. acnes*, **oxytetracycline** generally requires higher doses and more frequent administration, which can lead to poorer patient compliance. - It often causes **gastric irritation**, making it less favorable for long-term acne management. *Minocycline* - **Minocycline** is also effective for acne but is associated with a higher risk of **side effects** like dizziness, headache, and hyperpigmentation (e.g., skin, teeth). - Its potential for **drug-induced lupus-like syndrome** and **hepatotoxicity** makes it less preferred compared to doxycycline, especially for prolonged use. *Demeclocycline* - **Demeclocycline** is primarily used as an **ADH antagonist** for treating syndrome of inappropriate antidiuretic hormone (SIADH) and is not a first-line treatment for acne. - It has a higher incidence of **photosensitivity** and overall greater renal toxicity compared to other tetracyclines, making it unsuitable for acne.
Question 7: A 25-year-old male university student presented with a history of multiple tick bites 45 days prior, followed by recurring episodes of high-grade fever, headache, myalgias, arthralgias, nausea, and occasional vomiting. Each episode lasted approximately 6-7 days with symptom-free intervals of 9-10 days. Physical examination revealed mild splenomegaly and skin lesions. A Wright stain of the patient's peripheral blood smear was performed. What is the first oral drug of choice for this patient?
- A. Doxycycline (Correct Answer)
- B. Amoxicillin
- C. Cefuroxime
- D. Erythromycin
Explanation: ***Doxycycline*** - The patient's presentation is classic for **tick-borne relapsing fever (TBRF)** caused by *Borrelia* species. - The **pathognomonic feature** is the **relapsing pattern**: recurring fever episodes (6-7 days) separated by **afebrile intervals** (9-10 days), which distinguishes TBRF from Lyme disease. - **Wright stain of peripheral blood smear** during febrile episodes typically reveals **spirochetes** (unlike Lyme disease where spirochetes are rarely visible in blood). - **Doxycycline 100 mg twice daily** is the **first-line oral treatment** for TBRF, with excellent activity against *Borrelia* spirochetes. - Also covers potential tick-borne coinfections (Ehrlichia, Anaplasma). *Amoxicillin* - While effective for **Lyme disease**, amoxicillin is **less effective for TBRF** compared to tetracyclines. - Used as an alternative in **pregnant women or children <8 years** when doxycycline is contraindicated. - Does not cover rickettsial coinfections that doxycycline would treat. *Cefuroxime* - This **second-generation cephalosporin** can be used as an alternative for Lyme disease. - However, it is **not the first-line choice** for the relapsing fever pattern seen in this case. - Doxycycline remains superior due to broader coverage and better efficacy for TBRF. *Erythromycin* - **Erythromycin** has **poor efficacy** against *Borrelia* species and is **not recommended** for TBRF or Lyme disease. - Higher relapse rates and treatment failures make it an inappropriate choice. - Modern macrolides (azithromycin) have better activity but still inferior to doxycycline.
Question 8: Drug Induced Lupus is caused by all except
- A. Hydralazine
- B. Sulphonamides
- C. Isoniazid
- D. Procaine (Correct Answer)
Explanation: ***Procaine*** - While **procainamide**, a derivative of procaine, is a known cause of **drug-induced lupus (DIL)**, **procaine** itself is not typically implicated. - Procaine is a **local anesthetic** and its mechanism of action does not commonly lead to the immunological reactions seen in DIL. *Hydralazine* - **Hydralazine** is a well-established cause of **drug-induced lupus (DIL)**, particularly with higher doses and prolonged use. - It frequently results in the development of **anti-histone antibodies**, a hallmark of DIL. *Sulphonamides* - Various **sulphonamide antibiotics** (e.g., sulfasalazine, sulfamethoxazole) are known to induce **lupus-like syndromes**. - These drugs can trigger immune responses leading to symptoms characteristic of **systemic lupus erythematosus (SLE)**. *Isoniazid* - **Isoniazid**, an anti-tuberculosis medication, is a recognized cause of **drug-induced lupus (DIL)**. - It often leads to the formation of **anti-histone antibodies** and clinical manifestations resembling spontaneous lupus.
Question 9: Best drug for the condition shown below is: (NEET Jan 2018)
- A. Ivermectin
- B. Doxycycline (Correct Answer)
- C. Sulphonamides
- D. Penicillin
Explanation: ***Correct: Doxycycline*** - The image shows a **tick embedded in the skin** with surrounding erythema, indicative of a **tick bite** and potential **Lyme disease** or other tick-borne infections. - **Doxycycline** is the **drug of choice** for early Lyme disease (caused by *Borrelia burgdorferi*) and many other common tick-borne illnesses like Rickettsial infections (e.g., Rocky Mountain Spotted Fever) and Anaplasmosis. *Incorrect: Ivermectin* - **Ivermectin** is primarily used to treat **parasitic worm infections** like onchocerciasis, strongyloidiasis, and scabies. - It is **not effective** against bacterial infections transmitted by ticks. *Incorrect: Sulphonamides* - **Sulphonamides** are a class of **antibiotics** effective against various bacterial infections, but they are generally **not the first-line treatment** for tick-borne diseases. - For tick-borne illnesses, **doxycycline** typically has broader and more effective coverage. *Incorrect: Penicillin* - **Penicillin** is an **antibiotic** primarily effective against a range of gram-positive and some gram-negative bacteria, and spirochetes like *Treponema pallidum*. - While it has some activity against *Borrelia burgdorferi* (Lyme disease), **doxycycline is preferred** for early-stage Lyme disease and is specifically active against other common tick-borne pathogens where penicillin is not.
Question 10: Which of the following reduces the efficacy of oral contraceptives?
- A. Griseofulvin (Correct Answer)
- B. Disulfiram
- C. Erythromycin
- D. Cimetidine
Explanation: ***Griseofulvin*** - **Griseofulvin** is an antifungal agent known to induce liver enzymes, specifically the **cytochrome P450 system**. - Enzyme induction accelerates the metabolism and clearance of **oral contraceptives**, leading to lower plasma concentrations and reduced efficacy. *Erythromycin* - **Erythromycin** is a macrolide antibiotic that typically inhibits liver enzymes rather than inducing them. - While it can interfere with the metabolism of some drugs, it usually **increases** rather than decreases the plasma levels of co-administered medications, and is not known to reduce oral contraceptive efficacy. *Disulfiram* - **Disulfiram** is used to treat chronic alcoholism and inhibits aldehyde dehydrogenase. - It does not significantly interact with the metabolism of **oral contraceptives** via the cytochrome P450 system or other mechanisms that would reduce their efficacy. *Cimetidine* - **Cimetidine** is an H2 receptor antagonist that is known to inhibit cytochrome P450 enzymes. - This inhibition would likely **increase** the plasma concentration of drugs metabolized by these enzymes, such as oral contraceptives, rather than reducing their efficacy.
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